A power transmission device of a hybrid vehicle including an electric motor inside a case is disposed with a lubrication device for supplying oil to the electric motor and a gear member requiring lubrication. A heating part cooling structure for a vehicle drive device described in Patent Document 1 is an example thereof. The heating part cooling structure of Patent Document 1 is disposed with a catch tank 52, a first oil passage 61 for supplying oil to a first generator motor 13, and a second oil passage 62 for supplying oil to a second generator motor 14 on the upper side of a case 10. Oil is forcibly transferred from an oil pump 20 and supplied to the second oil passage 62 and the catch tank 52, and oil is scraped up by rotation of gears and supplied to the catch tank 52. The first oil passage is configured to be supplied with oil when oil accumulated in the catch tank 52 reaches a predetermined oil level. In a heating part cooling structure configured as described above, when the oil accumulated in the catch tank 52 is at a lower oil level, the oil is preferentially supplied to the second generator motor 14. A lower oil level in the catch tank 52 corresponds to a relatively lower vehicle speed state, i.e., a running state in which a running mode using the second generator motor 14 (motor running mode) is frequently used and, since the oil is preferentially supplied to the second generator motor 14 in this case, the second generator motor 14 is efficiently cooled.